Find out how many calories your body needs at rest and in daily life, so you can fuel yourself with confidence.
Your BMR and TDEE are two of the most important numbers for understanding how your body uses energy. Knowing them helps you make informed decisions about how you fuel yourself – without guesswork or extremes.
Basal Metabolic Rate is the energy your body needs just to stay alive at complete rest. Heart beating, lungs breathing, cells repairing. For most women, this falls between 1,200 and 1,600 calories per day. Think of it like the electricity bill for a house when nobody's home. Your BMR is the absolute floor of what you should be eating.
Total Daily Energy Expenditure is your BMR plus everything else: walking, working, cooking, exercising, fidgeting, thinking. This is the total energy your body actually uses in a day, and the more useful number for planning your nutrition.
Most of your energy (60-70%) goes on your BMR. Daily movement (NEAT) accounts for 15-30%. Digesting food (TEF) uses about 10%. And formal exercise is typically the smallest component at just 5-10%.
Most crash diets put you well below your BMR. Your body responds by slowing your metabolism, conserving energy, breaking down muscle for fuel, and holding onto fat stores. The exact opposite of what you want. A gentle deficit of around 80% of your TDEE, but never below your BMR, supports gradual, sustainable change.
This is the foundation of how F.L.A.M.E approaches nutrition: nourishment over deprivation, knowledge over guesswork. When you understand what your body actually needs, everything changes.
Basal Metabolic Rate
–
calories/day
burned at rest
Total Daily Energy Expenditure
–
calories/day
including all daily activity
These numbers are a starting point, not a prescription. Every body is different, and no calculator can account for your unique metabolism, hormones, stress levels, or history. Your body will always tell the true story. If you'd like personalised support in understanding and working with your body, we'd always recommend working with a qualified coach.
Want to understand these numbers better? Read the full guide →
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BMR stands for Basal Metabolic Rate. It's the number of calories your body needs just to stay alive at complete rest. For most women, this falls between 1,200 and 1,600 calories per day. You should never consistently eat below your BMR.
TDEE stands for Total Daily Energy Expenditure. It's your BMR plus all the energy you use through daily movement, exercise, and digestion. This is the more useful number for planning your nutrition.
This calculator uses the Mifflin-St Jeor equation, considered the most accurate BMR formula for the general population. It accounts for your weight, height, age, and gender, then multiplies by an activity factor for your TDEE.
A sustainable approach is to eat around 80% of your TDEE – a gentle 20% deficit. Crucially, never eat below your BMR. Crash diets that push you well below your BMR slow your metabolism and are not sustainable.
Your BMR is the minimum energy your body needs to function. Consistently eating below it signals to your body that there isn't enough fuel. It responds by slowing metabolism, conserving energy, breaking down muscle, and holding onto fat – the opposite of what most people want.
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